Refrigerating apparatus of the compression type



' June 13; 1939.-

R. HINTZE REFRIGERATING APPARATUS OF THE COMPRESSION TYPE Filed Dec. 16, 1957 2 Sheets-Sheet l v June 13, 1939.

REFRIGERATING APPARATUS OF THE COMPRESSION TYPE R. HINTZE Filed Dec. 16, 1957 2 sheets-sheet 2 Patented June 13, 1939 REFRIGERATIN G APPARATUS OF THE COM- ,PRESSION TYPE Rudolf Hintze, Berlin-Charlottenburg, Germany,

assignor to Siemens-Schuckertwerke Aktiengesellschaft, 'Berlin-Siemensstadt, Germany, a corporation of Germany Application December 16,1937, Serial No. 180,195 In Germany December 24, 1936 12 Claims.

The present invention relates to improve-' ments in refrigerating apparatus of the compress type, andmore particularly to a control therefor.

a In refrigerating apparatus of the compression type it is known to supply the refrigerant, liquefied in the condenser, to a collecting tank, whence the condensate passes into the evaporator under control of a valve. In the known arm rangements of this kind, the valve is directly operated by a float arranged in the collecting tank. Since there is a considerable difference in pressure between the condenser and the evap orator of the refrigerating apparatus, great con- 15 trol forces must sometimes be exerted by the float. This causes the valve 'to be suddenly opened upon the liquid level in the tank exceeding a given value so that a relatively large quan tity of refrigerant is allowed to flow into the 20 evaporator.

The object'of this invention is to provide an arrangement, whereby the flow of the refrigerant into the evaporator is rendered as uniform as be spaced, if desired, from the point where the valve is located. The adjusting forces released by the float may be easily transmitted to the distant control point by electric conductors. Fur- 35 thermore, by suitably dimensioning the electromagnet-it is easily possible to arrange that the valve is opened and closed in accordance with the difference in pressure prevailing between the condenser and the evaporator only when the liquid level in the collecting tank has attained a given height. With the aid of the float, a switch may be operated which closes, upon the attainment of a given liquid level within the collecting tank, the exciting circuit of the electromag- 45 net, thus causing the valve to open. The governor controlled by the float serves to adjust a resistance lying in the circuit of the electromagnet. In this manner without the electromagnetic circuit being interrupted, the exciting cur- 5 rent of the electromagnetically controlled valve is increased upon the attainment of a given liquid level within the collecting tank to such a value that this valve is opened.

The invention is, for instance, particularly ad- 5 vantageou's in connection with such arrangements in which the refrigerant compressor, the condenser and the float valve are arranged below the cooling chamber of a refrigerator, a conduit extending from the float valve to the" evaporator arranged in the cooling chamber at the upper part thereof. Since in this case, the conduit leading to the evaporator is under the pressure prevailing in the condenser, a particular lagging of this conduit, or special .valves for increasing the pressure in this conduit are not necessary. These means had to be employed in the refrigerating apparatus of the compression type hitherto known in order to prevent the conduit extending from the float valve to the evaporator from being covered with hoarfrost owing to the undesirable evaporation of the refrigerant;

The member controlled by the float may also be designed in such a manner that it varies by its movement a reactance, i. e. an inductive or capacitive resistance, lying in the main circuit of the electromagnet controlling. the valve. In this manner it is possible to design the control member in such a manner that no current interruptions occur as well as no sliding of the movtive position with respect to an iron core is varied in accordance with the liquid level in the'collecting tank. In this case the movable float may be either connected to the iron core and the current traversed coil firmly secured within the collecting tank, or vice versa, the first mentioned arrangement being particularly advantageous sinceno movement of current carrying parts is required when governing. Another modification of the invention employs for adjusting the valve a variable plate condenser whose coatings are in part firmly secured to the collecting tank and in part to the movable float.

In the accompanying drawings are shown I05 to the tank H2.

Fig. 3 shows a modifled wiring diagram of the control member of Fig. 2, and

Fig. 4-illustrates a modification of the arrangement shown in Fig. 2.

Referring to Fig. 1, I denotes a collecting tank for the liquefied refrigerant flowing through the conduit 2 from the condenser (not shown) into tthe tank from which a conduit 8 extends to the valve 4, the refrigerant passing thencethrough the conduit 5 to the evaporator (not shown) of the'refrigerating apparatus. The flow of therefrigerant from the collecting tank I into the evaporator is controlled with the aid of a float 6 in accordance with the liquid level in the "tank I. To the float 6 is rigidly secured a governor arm I rotatably mounted as indicated at 8. The gov ernor lever 'I adjusts a series resistance 9 lying in the circuit of the electromagnet I0 of the valve. The valve has an armature II held in the position shown by a spring I2 and a slide I3 pivotally secured to the armature II as indicated at II. The slide cooperates with the valve seat 5 to which is connected the discharge conduit 5 for the condensate. The slide I3 is pressed against the valve seat by a spring I6. II denotes a switch actuated preferably simultaneously with the operating switch of the refrigerating apparatus; i. e., the switch is closed when putting the refrigerating apparatus into operation. In this manner the exciting current c rcuit for the electromagnet I0 is closed. The condensate collecting in the tank I raises the slide 6 and therefore cuts out the resistance 9 gradually from the exciting circuit, so that upon the attainment of a given liquid level the exciting current of the electromagnet I0 sumces to close the valve.

In the embodiment shown in Fig. 2 are arranged below the cooling chamber IOI the motor compressor set I02, the condenser I03, a ventilator I04 for'circulating the cooling air and a float tank I06. In the latter is placed a float I06 secured to an ironcore I01. The iron core I01 cooperates with a coil I08 which lies in the circuit of the electromagnet I09 serving to operate a valve H0. The latter controls the flow of the liquid refrigerant into the evaporator III arranged in the upper part of the cooling chambar. The electromagnet I09 and the valve IIO are located in a casing II2 connected directly to the collecting tank through a short conduit II3. A conduit III leads directly from the float tank The vaporous refrigerant flows from the evaporator III through a conduit H5 back into the suction side of the compressor I02. 4

The control circuit for the electromagnet I09 is connected to the alternating-current supply circuit" III-II8. The above-described arrangement operates as follows:

Since as above described the iron core I0! is the evaporator III through the conduit Ill. Ac-

cordingly, the liquid level in the tank I05 lowers and the iron core I" moves in the downward direction. The increase in resistance of the coil I08 caused thereby, weakens the exciting current of the electromagnet I09 to such an extent that the valve H0 is again closed under the action of the compression spring H9.

The coil I08 and the electromagnet I09 may also be connected in parallel as is schematically shown in Fig. 3. In this case upon the upward movement of the iron core I0'I within the coil I08, the resistance of the coil I08 is reduced to such an extent that the current flowing through the magnetic coil I09 is'no longer sufliclent to permit the magnet to hold the valve firmly seated. In this connection a tension spring may be allotted to the valve the force of which being then sufiicient to open the valve. V

The conductors I20, I2I connecting the coil I 08 arranged in the tank I06 with the electromag- 'net I09 mounted in the casing II2 may under certain circumstances also be arranged In the conduit II 4. The entire electric part of the con trol may be placed outside the system containing the refrigerant. Inthis case the magnetic flux traverses the thin sleeves of suitable material and passes into the interior of the system. Such an arrangement is shown in Fig. 4 in which the corresponding parts are denoted by the same numerals as in Fig. 2. The coil I08 which is controlled by the iron core I01 of the float I06 and the electromagnet I09 serving to control the valve IIO are arranged outside the system for the refrigerant; i. e., the coil I08 surrounds a sleeve I22 within which the iron core I01 controlled by the float I06 moves in the upward or the downward directiondepending upon the liquid level. The electromagnet I09 surrounds a tube I23 in which the valve H0 is mounted.

What is claimed is:

1. With a refrigerating apparatus having a circulati ng system for the refrigerant, comprising a compressor, a condenser, a condensate collect ing tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through 'saidconduit,'a float arranged in said tank, an adjustable im pedance regulator connected with said float so as to have its impedance value varied responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said impedance and said valve.

2. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduitsconnecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising an eletfiomagnetically coi'i'trolled valve arranged in the conduitbetween said tank and said evaporator for controlling the flow of the refrigerant through said conduit, said valve being. designed to assume an intermediate control position between its on and off, positions, a. float arranged in said tank, a regulator having more than two regulating positions, said regulator being connected with said float so as to be operated responsive to variations of the level of. the refrigerant in said tank, and a control circuit oper-. atively connecting said regulator and said valve.

3. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits connecting said Y compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, a float arranged in said tank, a regulatable impedance mounted in said tank and connected with said float so as to be varied responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said impedance and said valve.

4. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising an electromagnetically controlled valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, said valve being designed to assume an intermediate control position between its on and fofi" positions, a float arranged in said tank, a resistor designed to be adjusted to several resistance values, said resistor being mounted in said tank and connected with said float so as to be adjusted responsive to variavalve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, a float arranged in said tank, a variable inductive control member mounted in said tank and connected with said float so as to have its inductance value varied responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said inductance and said valve.

6. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, 8. float arranged in said tank, a control device having an inductance coil and an iron core movable relatively to each other, said control device being mounted in said tank and connected with said float so as to have the relative position of said coil and said core varied responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said coil and said valve.

7. With a refrigerating apparatus having a cir-- culating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, 9. float arranged in said tank, a control device arranged within said tank and having an inductance coil and an iron core movable relatively to each other, said coil being firmly secured to said tank, said core being connected with said float so as to be moved responsive to variations of the level of.

tank, and evaporator, in combination, a regu1at*- ing system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, said valve having electromagnetic actuating means, a float arranged in said tank, a variable impedance connected with said float so as to be adjusted responsive to variations-of the level of the refrigerant in said tank, and a control circuit operatively connecting said valve actuating means and said impedance, said evaporator and said valve being arranged in said cooling chamber, and said compressor, condenser and tank being arranged outside of said chamber.

9. In a refrigerator of the cabinet type having a cooling chamber, a drive motor, and a refrigerating system comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits conecting said compressor, condenser, tank, and evaporator, in combination, a

regulating system comprising a valve arranged in the conduit between said tank and said evaporator for controlling the flow of the refrigerant through said conduit, said valve having electromagnetic actuating means, a float arranged in said tank, a variable impedance connected with said float so as to be adjusted responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said valve actuating means and said impedance, said evaporator and, said valve being arranged in said cooling chamber, andsaid drive motor, compressor, condenser and tank being arranged below said cooling chamber.

10. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, a condenser, a condensate collecting tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and saidevaporator for controlling the flow of the refrigerant through said conduit, a float arranged in said tank, an inductive regulator having an inductance coil arranged exteriorly of said tank and an iron. core arranged within said tank and connected with said float so as to vary the inductivity of said coil responsive to variations of the level of the refrigerant in said tank, and a control circuit operatively connecting said coil and said valve.

11. With a refrigerating apparatus having a circulating system for the refrigerant, comprising casing for operating said valve, a float arranged in said tank, an electric regulator connected with said float so as to be adjusted responsive to variations of the level of the refrigerant in said tank, and an electric circuit connecting said electromagnet with said regulator.

12. With a refrigerating apparatus having a circulating system for the refrigerant, comprising a compressor, av condenser, a condensate collecting tank, an evaporator, and conduits connecting said compressor, condenser, tank, and evaporator, in combination, a regulating system comprising a valve arranged in the conduit between said tank and said evaporator for control- RUDOLF Hm'rzn. 

